! to tweet: http://clicktotweet.com/lfi0w . The audio on this is unedited apart from a bit of amplification due to the subject matter. This is about clicks, which are used by people all over the world but rarely in actual words. The only languages which use clicks as ordinary speech sounds are the Khoisan languages of Southern Africa and the nearby though unrelated Bantu languages as loanwords, such as with Swahili and Zulu. However, they do occur elsewhere, for instance one register of an Australian aboriginal languages uses an egressive click and around the Eastern Mediterranean, a tut represents the word "no" sometimes, so it can happen. Apparently German also produces clicks on occasion, though i've never heard them.

Xhosa and Zulu therefore contain words with clicks in them, and in fact Xhosa (Nelson Mandela's mother tongue) has enough for a tongue-twister: Iqaqa laziqikaqika kwaze kwaqhawaka uqhoqhoqha - the skunk rolled over and ruptured its larynx. This is presumably a loose translation as the sentence does not seem to contain a Native American loanword and skunks are not native to Southern Africa.

Some clicks, such as the bilabial and retroflex clicks, are among the rarest sounds in human language, being found in only single languages. Others are found in interjections and other utterances in English, such as the clopping noise, the "tsk" or "tut" of irritation, or the kissing sound. They're unusually loud and, also unusually, can be pronounced while holding one's breath, although i exaggerate this in the video because in fact there are some other speech sounds which are like this. The San people may also be particularly good at making clicks because their hard palates are higher than most other people's.

One of the reasons i spend so long fiddling with the audio on YouTube videos is my habit of inserting alveolar clicks at the start of words where other English speakers would use a glottal stop. These are sometimes simultaneously articulated with other consonants such as S, and i often have to spend ages removing them from the audio files. This demonstrates, however, that like other Germanic languages, Arabic and Hebrew, there are no words which always begin with a vowel in English. However, English often elides the glottal stop in the middle of a phrase. This does not occur in most other Germanic languages. For instance, i once attempted to say "Das ist ein Problem" in German (That's a problem) but it got heard as "Das ist dein Problem" - "that's your problem". Unlike German however, some English accents, including mine in a certain register, use glottal stops as phonemes, as in the Cockney "wo' a lo' o li'l bo'ls". Danish also has a glottal stop as a phoneme but not in the same context.

A related subject is that of the pharyngeal plosives. Just as it may be that the Bushmen of the Kalahari and their female relatives, in other words the San people, can pronounce clicks well due to their anatomical differences, the pharyngeal plosives are probably absent from all languages because many people lack the necessary muscles to pronounce them, a problem which is particularly pronounced in the Far East where something like one person in five cannot completely close their pharynx voluntarily. This means that there would be a widespread unaddressable speech impediment in a large fraction of the population of speakers of any language which used pharyngeal stops, which is presumably the reason why they never occur. However, other pharyngeal consonants are widespread in Afro-Asiatic languages such as Arabic, Egyptian and Biblical Hebrew, which raises the question of whether people from the Far East find it harder to pronounce them.